Toby and the Stout Gentleman - S1-E21
Revealing mistake: In a close up of Sir Topham Hatt, the camera shakes.
Toby and the Stout Gentleman - S1-E21
Revealing mistake: The water is not flowing when Toby passes Arlesdale Lake.
Thomas the Jet Engine - S6-E22
Revealing mistake: After Cranky unloads the jet engine, it is already turned on.
Audio problem: At the beginning of the episode, Gordon has Edward's whistle sound.
Continuity mistake: The children waving at Toby disappear after Toby puffs under the bridge.
Continuity mistake: Alicia Botti was annoyed by Toby's appearance. But in "Thomas, Percy, and the Squeak", she thought Percy being dirty was the proper appearance of a steam engine.
Other mistake: Duck stops at Arlesburgh West Station for 5 seconds, which is not enough time to let passengers board his train.
Revealing mistake: When the boys sing, the camera shakes.
Character mistake: The driver said that Bill and Ben's names and numbers would be taken away, but the twins do not have numbers.
It's Good to Be Gordon - S10-E9
Character mistake: The narrator refers to Henry as "Henry's engine."
Other mistake: The narrator says that the fence was mended, but there is no fence and there never was.
Revealing mistake: In a close up of Edward, he has Thomas' whistle sound and no tender.
Plot hole: James appears in every episode before his introduction in "Thomas and the Breakdown Train." Also, James is supposed to be black, because at the end of the episode, James is told he will get a different coat of paint. (He is also black in the book).
Deliberate mistake: Due to the production order, Arthur can be seen at the quarry, but his introduction is 6 episodes later, in "The Spotless Record."
Factual error: Black smoke comes out of Henry's cylinders, when it should only be coming out of his funnel.
Revealing mistake: When Thomas leaves Dryaw, in the background, the biplane's propeller stops spinning, revealing that the propeller is actually a CD.
Character mistake: The narrator says that Thomas had never delivered the mail before, but he did in Season 4.
Other mistake: Mavis and Cranky should've realised that Thomas woke them up the first time he blew his whistle.
Other mistake: In the very first shot of Spencer, his coaches aren't textured.
The Biggest Present of All - S13-E16
Audio problem: When Henry and James are at the quarry, their whistle sounds are played out of order.
Answer: He was in the water.